There are a few different types of canning kits available from a number of manufacturers, though they typically come down to either pressurized or water bath kits. Pressurized kits are designed to use heated steam and pressure to create an extremely hot environment in which low acidity foods, such as meats and fish, can be canned and preserved safely. Water bath kits are basically large pots in which jars can be submerged in boiling water to produce the heat necessary to safely can foods that are higher in acidity. There are also some canning kits for those who already have a pressurized or water bath canner, which usually include jars and other canning tools.
The two most common types of canning kits are based on the method used to produce the heat necessary for safe canning and food preservation. For low acidity foods, including most vegetables and meats, a pressurized canner is used to achieve temperatures higher than what is possible from boiling water. Pressurized canning kits usually include a pressurized canner, which is a large pot designed to create and handle a great deal of internal pressure, and canning tools. These tools include a jar lifter, a magnetic lid lifter, and canning jars.
There are also canning kits designed to help someone first getting started with water bath canning. For foods that are higher in acidity, including many fruits and tomatoes, the temperature required to safely can them can be achieved by boiling water. Water bath canning kits include a water bath pot, which is basically a large pot in which jars can be placed and covered with water, as well as the same tools included in pressurized kits. Both types of kits typically include a rack that can be put on the bottom of the canner pot, on which the jars are placed during canning.
Some canning kits are designed to help anyone who is starting out, without an actual canning device being included. People who already have pots large enough to perform water bath canning in, for example, can choose these kinds of kits to obtain the necessary jars and tools for canning. These canning kits usually include a jar lifter, which is used to remove the hot jar from the canning pot, and a magnetic lid lifter that is used to pick up lids from hot water in which they are cleaned and held prior to canning. Such kits can also include a funnel for easily getting food into a jar and a small spatula to wipe the top edge of the jar clean of food before canning.